Laser printers and xerographic copiers employ a dry powder toner to produce the copied image. To assist in the production of such images, the toner powder is usually magnetic. Recently, production has turned to the development of reusable toner cartridges, which can be refilled with new toner powder and the cartridge reinserted into a printer. The refilling of toner powder in a cartridge has a critical point relative to the removable cover of the body which contains the toner to prevent the toner powder from leaking along the sides of the removable cover. Due to the extremely messy nature of toner, it is desirable to prevent or avoid as much of this leakage as possible.
The recycling of used toner cartridges requires two basic steps: the insertion of a removable cover over the exit opening of an empty cartridge; and the filling of the empty cartridge body with new toner powder. Since the filling takes place while the cartridge is assembled, the insertion of the removable cover is performed without any possibility to verify that the surfaces which the cover enclose are completely clean, ensuring a tight seal. In the manufacture of new toner cartridges, the original seal for the toner reservoir usually comprises a thin vinyl strip of plastic that is heat fused on a seal plate which extends around the perimeter of the toner reservoir prior to the operative connection of a roller housing to the reservoir housing. Then the reservoir housing is heat welded to the roller housing and these housings for all practical purposes become one unit in which the seal plate is disposed intermediate the juncture of the roller housing and the reservoir housing.
When the new cartridge is ready to be used by the customer, the original toner reservoir seal is manually removed, thereby exposing a peripheral recess that had been created between the reservoir housing the roller housing to accommodate the original removable cover. This peripheral recess or cavity as will be explained later in greater detail becomes crucial to the recharging and sealing aspects of the present invention. Obviously once the original reservoir seal has been removed there is nothing to prevent the toner from getting into the remainder of the cartridge system; and, thus a replacement sealing means must be employed in order to enable the toner cartridge to be recharged with toner and thereby be suitable for recycling.
There have been various prior art attempts to solve the above problem, see for example, U.S. Pat. No. 4,862,210 to Woolley and U.S. Pat. No. 5,080,745 to Paull. The disclosures of both of these patents is hereby incorporated by reference.